This relates generally to electronic devices, and more particularly, to electronic devices with displays.
Electronic devices often include displays. For example, cellular telephones and portable computers often include displays for presenting information to a user.
Liquid crystal displays contain a layer of liquid crystal material. Pixels in a liquid crystal display contain thin-film transistors and electrodes for applying electric fields to the liquid crystal material. The strength of the electric field in a pixel controls the polarization state of the liquid crystal material and thereby adjusts the brightness of the pixel.
Layers of dielectric such as layers of silicon oxide and silicon nitride may be used in forming the thin-film transistors and other pixel structures in a liquid crystal display. These dielectric layers may have different indices of refraction. For example, a silicon nitride layer may have an index of refraction of about 1.9 and a silicon oxide layer or other dielectric layer may have an index of refraction of 1.51. If care is not taken, index of refraction discontinuities at the interfaces between the dielectric layers in a display may give rise to unwanted reflections and transmission loss. The dielectric layers may also unintentionally serve as a dielectric interference filter, which can lead to undesired off-axis shifts in display color (i.e., color shifts that vary as a function of off-axis viewing angle).
It would therefore be desirable to be able to provide improved displays for electronic devices such as displays with enhanced transmission and reduced off-axis color shifts.